One increasingly popular application for wireless systems are wireless local area networks (WLANs) of computer systems. Prominent in the field of home and business, wireless computer networks include the wireless standards known as 802.11. The first standard to be available in commercial products was 802.11b. It supports data rates from 1 Mb/s to 11 Mb/s. To ensure data integrity at such data rates, the communication encompasses many considerations, including equalization of distortion.
Decision feedback equalizations (DFE) are known to be powerful methods to equalize a distortion caused by multi-path channels, and still have rather small implementation complexities. However, if the communication system utilizes error correction codes, a DFE is not possible to implement due to a delay required for decoding of the error correction code, which makes the decision for the feedback no longer available for the equalization of a next symbol.
One of the ways to resolve such a problem is to use a raw symbol for a decision before the post cursor cancellation by the feedback equalization filtering and after the feed forward equalization filtering. But in this technique the raw symbol used to make a decision has post cursor interference, and the probability of decision error is higher. Once the decision error happens, equalization for the next symbol will not be as reliable as a correct decision case. Because of this, the raw symbol based decision schemes suffer severe performance degradation, especially when the coding gain is larger.
Accordingly, a need exists for an optimal equalization algorithm for a communication system with block code based error correction that resolves the delay of decision availability. The present invention addresses such a need.